As expected, the GeForce GTX 680 SLI configuration is the fastest solution according to 3DMark Vantage, beating the dual-GPU GeForce GTX 690 by 2-4%. The efficiency of the SLI technology depends on load: the two GeForce GTX 680s are only 49% ahead of the single such card at the Performance settings but enjoy an 82% advantage at the Extreme settings. The GTX 680 SLI is also 7 to 18% ahead of the overclocked tandem of Radeon HD 7970s.
3DMark 2011 agrees with its predecessor but the SLI tandem is even more efficient here, outperforming the single GTX 680 by 71-93% and the dual-chip GeForce GTX 690, by 6%.
Unigine Heaven Demo
Although SLI is just as efficient here as in 3DMark, the SLI tandem is only 2-3% ahead of the GeForce GTX 690. The Radeon HD CrossFireX configuration clocked at 1000/5800 MHz is very close, too, and even beats its opponents when we enable antialiasing.
S.T.A.L.K.E.R.: Call of Pripyat
This game produces interesting results:
The pair of GeForce GTX 680s isn't much better than the dual-chip GeForce GTX 690 despite the latter's lower clock rates. Take note that the bottom frame rate of the GTX 690 is often higher than that of the SLI tandem. It’s also interesting that the Radeon HD 7970 CrossFireX overtakes the GeForce GTX 680 SLI at higher loads when the game needs more and faster graphics memory.
Left 4 Dead 2
Our platform isn’t fast enough for the tested solutions to show their best in Left 4 Dead 2. It is only at 2560x1600 with 8x MSAA that the graphics cards differ, the Radeons being slightly ahead of their opponents (thanks to the increased clock rates).
Metro 2033: The Last Refuge
The GeForce GTX 690, GeForce GTX 680 SLI and Radeon HD 7970 CrossFireX are almost equal in this test. They are all equally slow at 2560x1600, however odd this statement may sound in reference to such expensive graphics hardware.